The present invention is related to devices for the collection of specimen, e.g., oral fluid, urine, or the like, and to diagnostic testing. The device of the present invention provides an absorbent foam member on a handle, and a housing for delivering the fluid specimen from the foam member onto a test membrane. More specifically, the device further includes a fluid chamber, within the housing, into which the fluid specimen from the foam member is deposited. The specimen that collects in the fluid chamber passes through an aperture in the fluid chamber and onto the test membrane located beneath the aperture. If the capacity of the fluid chamber is exceeded, the excess specimen may flow into a backup chamber where it may be retained or reabsorbed by the foam member. The device is particularly useful for the collection and testing of a specimen from a mammal while maintaining aseptic conditions.
Various methods and devices have been used to collect and deliver specimen for diagnostic testing. One conventional method for collecting an oral fluid specimen is to use a cotton swab. The oral fluid sample can then be applied to a test device by contact with the swab or the sample can be rinsed from the swab.
Various devices comprising test tube like structures with sample absorbing means have been described for collecting biological samples for diagnostic testing. Examples of such devices are described in U.S. Pat. Nos. 4,123,224, 5,000,193, 5,022,409, 5,260,031, 5,268,148, 5,283,038, 5,339,829, 5,376,337, 5,380,492, 5,393,496, 5,479,937 and 5,494,646.
In a copending application, U.S. Ser. No. 08/712,682, a simple device for collecting and delivering a specimen for diagnostic testing is described. In accordance with the disclosure, a specimen collecting device comprises an elongated foam member having a longitudinal axis and an uncompressed cross sectional area, the elongated foam member being circumscribed by a hollow tubular member along a portion of the longitudinal axis, the hollow tubular member having a cross sectional area less than the uncompressed cross sectional area of the foam member so that the foam member is compressed along the circumscribed portion.
In another copending application, U.S. Ser. No. 08/869,105, filed Jun. 4, 1997, now U.S. Pat. No. 5,922,614 an improved device for collecting and delivering a specimen for diagnostic testing is disclosed, wherein the device provides a simple and convenient method for extracting the sample from a foam member. According to the disclosure, an embodiment of a specimen collecting device includes an elongated foam member having a longitudinal axis and an uncompressed cross sectional area, the elongated foam member being circumscribed by a hollow tubular member along a portion of the longitudinal axis, the hollow tubular member having a cross sectional area less than the uncompressed cross sectional area of the foam member so that the foam member is compressed along the circumscribed portion. Around the hollow tubular member is a flexible sleeve member having a first end that fits snugly around the hollow tubular member and a second end with an enlarged diameter that can surround the uncompressed foam member. Conveniently, the sleeve member can be moved along the hollow tubular member to cover and uncover the portion of the foam member that is not circumscribed by the hollow tubular member. Further, by sliding the flexible sleeve member along the hollow tubular member to cover the foam member and by squeezing the foam member through the flexible sleeve member, a portion of the fluid absorbed by the foam may be extracted.
The present invention provides a simplified and improved device for the collecting and diagnostic testing of a specimen. In particular, the present invention provides a simple and convenient method and device for obtaining a specimen sample on a foam member and testing the sample by delivering the sample to an integral diagnostic test membrane held within the device.
In accordance with the present invention, a specimen collecting and testing device comprises an elongated handle member having a foam member at an end thereof. The handle member is slidable within a hollow, elongated housing member, which holds the test membrane in a stationary position so that the specimen can be expressed from the foam member and deposited onto the test membrane. The foam member is positioned outside the housing member for sample gathering. Once the specimen has been collected by the foam member, the device is held vertically with the foam member pointing upwards. The handle member is then drawn downwards, thereby drawing the foam member into and through the housing member. As the foam member is drawn through the housing, the foam member expels specimen, which travels downwards by gravitational forces into a fluid chamber located within the housing. The device is then held horizontally or placed horizontally on a surface and the specimen is deposited onto the test membrane to react with the test chemistry carried thereby.
According to one embodiment, the foam member comprises a material which, when wetted by the sample specimen, will expand from its dry configuration and, when compressed, will express specimen.
In one embodiment, the foam member, when wetted, will have a cross sectional area that is greater than at least a portion of the housing member such that, when the handle member is drawn through the housing member, the foam member is compressed, thereby expressing specimen into the fluid chamber.
In another embodiment, after specimen has been collected in the foam member, the device is held vertically with the foam member pointing upwards as the foam member is drawn through the housing member. A barrier located proximate the fluid chamber compresses the foam member as the foam member passes through the housing member. The compression of the foam member expresses specimen, which is deposited into the fluid chamber. The device is then positioned horizontally and the specimen in the fluid chamber passes through an aperture in the fluid chamber onto the test membrane.
Preferably, a backup chamber is located next to the fluid chamber such that if the fluid chamber""s holding capacity is exceeded, the excess specimen flows into the backup chamber where it may be retained or reabsorbed by the foam member. Thus, if a large amount of specimen is absorbed into the foam member, it may be expelled from the foam member into the fluid chamber and excess will then flow into the backup chamber to prevent excess specimen from being deposited onto the test membrane, which may negatively impact test results in some cases.
In a particularly preferred embodiment, the fluid chamber is designed to have a specimen holding capacity corresponding to particular volumes of specimen required for various specimen tests. If the specimen holding capacity is exceeded, the excess specimen will flow into the backup chamber, as described in more detail below.
In one embodiment, the foam member has a longitudinal axis and an uncompressed cross sectional area. The elongated foam member is circumscribed by a hollow, elongated handle along a portion of the longitudinal axis. In one embodiment, at least one portion of the hollow, elongated handle has an interior cross sectional area that is less than the uncompressed cross sectional area of the foam member, so that the foam member is compressed to deliver the sample to the fluid chamber located inside the hollow, elongated housing.
The diagnostic testing device of the present invention is particularly useful for collecting a sample of a fluid specimen and delivering the sample to a test membrane for a rapid one-step drugs of abuse test. It can also be used to provide fluid samples, particularly oral fluid or urine samples, for DNA testing for forensic and paternal identification, RNA testing, antibody testing, testing for disease, and other similar diagnostic procedures. The testing device of the present invention provides a simple and inexpensive method for collecting and testing the oral fluid sample. Further, in preferred embodiments of the invention, the foam member and fluid chamber of the diagnostic testing device will provide more consistent and accurate samples and test results.